To decorate the surface of various products, a decorative film for sticking to the surface thereof has hitherto been used. This decorative film comprises a substrate; an adhesive layer for sticking a decorative film to an adherend, formed on one surface of the substrate; a printed layer provided with a printed decorative pattern or character information, formed on the other surface of the substrate; and a top clear layer for protecting the printed layer.
This decorative film requires the stretchability for satisfying the conformability to the shape of the adherend surface and the surface property which prevents wrinkles from occurring after sticking, and also requires the weatherability and water resistance when used in vehicles and buildings. Furthermore, a substrate of this decorative film requires the printability for forming a printed layer. Therefore, soft polyvinyl chloride, which satisfies these requirements, has hitherto been used as the substrate of this decorative film.
However, the use of polyvinyl chloride has a problem that a plasticizer oozes out and a problem that a harmful chlorine-based gas is evolved on incineration and polyvinyl chloride is a chlorine salt of so-called dioxin. Therefore, the use of polyvinyl chloride tends to be globally restricted from an environmental point of view and materials, which satisfy the above requirements and can be replaced by vinyl chloride, are required as the substrate of the decorative film. It has been studied to use various soft polyolefins (for example, polypropylene and polyethylene) in place of polyvinyl chloride, however, these soft polyolefins have problems such as poor flexibility suited for a sticking operation to an adherend, and poor printability because of low surface energy. Therefore, these soft polyolefins are not necessarily suited for use in the decorative film.